Fuel cell systems include a fuel cell stack that produces electrical energy based on a reaction between a hydrogen-based feed gas (e.g., pure hydrogen or a hydrogen reformate) and an oxidant feed gas (e.g., pure oxygen or oxygen-containing air). The hydrogen-based feed gas and oxidant feed gas are supplied to the fuel cell stack at appropriate operating conditions (i.e., temperature and pressure) for reacting therein. The proper conditioning of the feed gases is achieved by other components of the fuel cell system to provide the proper operating conditions.
The fuel cell system includes an air compressor for compressing the oxidant feed gas and a heat exchanger for cooling the oxidant feed gas. The compressor provides the appropriate operating pressure of the oxidant feed gas and the heat exchanger provides the appropriate operating temperature of the oxidant feed gas. Generally, the fuel cell system also includes a humidifier to achieve the appropriate humidification condition of the oxidant feed gas for reaction within the fuel cell stack. A coolant system provides a means for heat to be rejected from the fuel cell stack and other system components.
The design of the oxidant feed gas supply system significantly influences the overall fuel cell system. More specifically, the oxidant supply system influences power draw on the fuel cell stack for operating compressor motors and the like, as well as loading the coolant system with waste heat. As a result, it is advantageous to improve the operating efficiency of the oxidant feed gas supply system.